1 files changed, 127 insertions, 0 deletions
diff --git a/include/mbgl/util/recursive_wrapper.hpp b/include/mbgl/util/recursive_wrapper.hpp
new file mode 100644
index 0000000000..a616805c0f
--- /dev/null
+++ b/include/mbgl/util/recursive_wrapper.hpp
@@ -0,0 +1,127 @@
+#ifndef MAPBOX_UTIL_VARIANT_RECURSIVE_WRAPPER_HPP
+#define MAPBOX_UTIL_VARIANT_RECURSIVE_WRAPPER_HPP
+
+#include <utility>
+
+namespace mbgl { namespace util {
+
+template <typename T>
+class recursive_wrapper
+{
+public:
+    using type = T;
+private:
+
+    T* p_;
+
+public:
+
+    ~recursive_wrapper();
+    recursive_wrapper();
+
+    recursive_wrapper(recursive_wrapper const& operand);
+    recursive_wrapper(T const& operand);
+    recursive_wrapper(recursive_wrapper&& operand);
+    recursive_wrapper(T&& operand);
+
+private:
+
+    void assign(const T& rhs);
+
+public:
+
+    inline recursive_wrapper& operator=(recursive_wrapper const& rhs)
+    {
+        assign( rhs.get() );
+        return *this;
+    }
+
+    inline recursive_wrapper& operator=(T const& rhs)
+    {
+        assign( rhs );
+        return *this;
+    }
+
+    inline void swap(recursive_wrapper& operand) noexcept
+    {
+        T* temp = operand.p_;
+        operand.p_ = p_;
+        p_ = temp;
+    }
+
+
+    recursive_wrapper& operator=(recursive_wrapper&& rhs) noexcept
+    {
+        swap(rhs);
+        return *this;
+    }
+
+    recursive_wrapper& operator=(T&& rhs)
+    {
+        get() = std::move(rhs);
+        return *this;
+    }
+
+
+public:
+
+    T& get() { return *get_pointer(); }
+    const T& get() const { return *get_pointer(); }
+    T* get_pointer() { return p_; }
+    const T* get_pointer() const { return p_; }
+    operator T const&() const { return this->get(); }
+    operator T&() { return this->get(); }
+};
+
+template <typename T>
+recursive_wrapper<T>::~recursive_wrapper()
+{
+    delete p_;
+}
+
+template <typename T>
+recursive_wrapper<T>::recursive_wrapper()
+    : p_(new T)
+{
+}
+
+template <typename T>
+recursive_wrapper<T>::recursive_wrapper(recursive_wrapper const& operand)
+    : p_(new T( operand.get() ))
+{
+}
+
+template <typename T>
+recursive_wrapper<T>::recursive_wrapper(T const& operand)
+    : p_(new T(operand))
+{
+}
+
+template <typename T>
+recursive_wrapper<T>::recursive_wrapper(recursive_wrapper&& operand)
+    : p_(operand.p_)
+{
+    operand.p_ = nullptr;
+}
+
+template <typename T>
+recursive_wrapper<T>::recursive_wrapper(T&& operand)
+    : p_(new T( std::move(operand) ))
+{
+}
+
+template <typename T>
+void recursive_wrapper<T>::assign(const T& rhs)
+{
+    this->get() = rhs;
+}
+
+template <typename T>
+inline void swap(recursive_wrapper<T>& lhs, recursive_wrapper<T>& rhs) noexcept
+{
+    lhs.swap(rhs);
+}
+
+}}
+
+#endif // MAPBOX_UTIL_VARIANT_RECURSIVE_WRAPPER_HPP